The July 6, 2013, Railway Disaster in Lac-Mégantic, Quebec Highlighted

The July 6, 2013, railway disaster in Lac-Mégantic, Quebec highlighted the danger that businesses can face when they are located close to rail lines, especially in the event of a derailment. One hundred and fifteen businesses were severely affected when an unattended train carrying crude oil derailed and crashed in the downtown area. Thirty buildings were completely destroyed, much of the downtown infrastructure (roads, utilities, and so on) was destroyed or severely damaged, and over 40 people died with many others seriously injured. While a runaway train may seem to be a rare occurrence, Canadian statistics indicate that, based on data from 2007-2011, on average there are 58 derailments annually, although not all of these involve dangerous goods.
-What is the dominating characteristic of an emergency, as illustrated by the Lac-Mégantic situation, which differentiates it from other occupational health and safety incidents?

A) it is sudden and requires an immediate response
B) it is often caused by humans.
C) it is always unpredictable
D) it can cause damage to life and property